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Glaucon joins the agora with its usual 30–40 patrons present, most of whom are idling or spectating. Glaucon has ambitious and unusual goals for his computing environment, and high standards of openness and freedom for the hardware he wants to use, but isn’t sure where to start implementing what he wants. Socrates, one of the regulars, having experience in this area, explains to Glaucon some of the subtleties of hardware being “open” or “closed”, and clears up some surprising misconceptions that Glaucon likely shares with others in his position.

Dramatis personae

In order of appearance:


Glaucon joins the agora for the first time. Those already present have just finished a bracing discussion on the applicability of blockchain technology to dishwashers.

Glaucon: why hello
Glaucon: I need some help with something
Glaucon: Does anyone know of any completely free hardware computers? I’m looking and I can’t find any
Thrasymachus: Who wants to tell him
Glaucon: I thought there were at least one or two
Glaucon: like a weak 16-bit/32-bit one at least
Socrates: Thrasymachus: why didn’t you mention POWER?
Thrasymachus: ?
Socrates: POWER is a remarkably open architecture
Thrasymachus: I wonder if it would meet Glaucon’s high standards
Adeimantus: it’s too new
Adeimantus: only the oldest workable tech will do, because performance is bloat
Socrates: Thinkpad with pre-ME CPU, Libreboot, and Trisquel
Socrates: no networking because I haven’t found an ISP that will give me the source to their CRM
Glaucon: people on /g/ are saying system76 but that’s not at all what I’m looking for
Glaucon: they’re all Intel or AMD CPUs
Glaucon: Pinebook is closer

The spectre of management engines

Thrasymachus: Socrates may be able to help you
Glaucon: hi Socrates
Glaucon: >OpenPOWER
Socrates: POWER arch, auditable/disablable management
Glaucon: this is exactly what I was looking for
Thrasymachus: Socrates wins
Glaucon: management?
Glaucon: like IME?
Socrates: OpenBMC
Glaucon: this is its own OS?
Glaucon: I’m still a bit lost
Socrates: Intel ME is a small CPU tacked on the side running Minix
Socrates: like it or not, management is actually pretty cool and useful
Socrates: the reason why ME is shit is because it’s not owned by you, so while you can control it (and it is useful for everybody), people don’t trust Intel to make it secure and safe against economic/political pressures
Glaucon: what if I wanted to avoid it entirely
Glaucon: that’s why I bought a 2003 Tower to begin with
Socrates: then disable it
Glaucon: there must be an option to have it not be there at all
Socrates: probably, if you email them they’ll probably ship it nulled out
Socrates: or give you instructions on how to do the same
Glaucon: do you know of any other boards like this you could link?
Socrates: nothing at this level ships without management
Socrates: (its not inherently bad)
Socrates: its basically just Wake-on-LAN but extended
Glaucon: what does ship without management
Socrates: to get stuff that ships without management you have to go into the low end devices that are used by people who don’t care about openness
Socrates: but genuinely, management is orthogonal to openness/security
Glaucon: such as?
Glaucon: ah shit, this board is $4k
Glaucon: lmao
Socrates: I mean, if you buy old pre-ME business laptops, they’re probably the best trade-off between good devices
Glaucon: that’s what I figured
Socrates: but really, don’t ask for “no management”, ask for management you can control
Socrates: its the difference between <manufacturer BIOS> and Libreboot, etc
Socrates: is probably a better explanation
Glaucon: so there essentially aren’t affordable options for open source CPUs at all
Socrates: OpenPOWER
Socrates: as was linked
Socrates: if you want to wait another decade, we might get some traction in RISC-V
Socrates: but for now, RISC-V competes with ARM, not Intel/AMD
Glaucon: that thing was 4000 bux
Socrates: listen bud freedom doesn’t come free
Glaucon: praise Jesus
Thrasymachus: fugg

The economics of open hardware

Glaucon: I don’t understand why I can’t get an SBC with an open source CPU
Socrates: that’s because you don’t understand market economics, but that’s OK
Socrates: if SBC grade is what you’re looking for, you can get RISC-V now for a shit perf:$ ratio, but a low absolute cost
Glaucon: okay
Glaucon: but a few hundred dollars would be possible
Glaucon: not just 4k
Socrates: probably we’re talking Raspberry Pi perf for the cost of a decent laptop
Glaucon: yeah that’s reasonable
Socrates: and no software support
Thrasymachus: I think I need to learn something about RISC-V
Socrates: basically just imagine the ARM product line but open source
Thrasymachus: I ain’t mad at that
Socrates: looks like you can get an unleashed board for ~$1000
Glaucon: still a bit high
Glaucon: but much more reasonable
Glaucon: maybe I’ll take the dive eventually
Socrates: sadly, that’s the two ends of the spectrum right now
Glaucon: It’s getting better
Socrates: you can get an Raspberry Pi for $1000, or you can get a POWER workstation for $5000
Glaucon: I might just get one of those Rockchip SBCs instead
Glaucon: or ARM SBCs
Glaucon: I don’t have 1000 bux to drop on a PC I want to use rarely
Socrates: Rockchip is ARM
Glaucon: right
Glaucon: well either way
Socrates: is Mali open source?
Socrates: I thought it needed blobs
Socrates: oh, ARM give you some open source userspace drivers
Socrates: standby for 0 perf lmoa :(((
Glaucon: if I was gonna just get an ARM SBC do you have any suggestions
Glaucon: I know the banana pi is mostly open software/hardware
Socrates: what’s your use case?
Glaucon: I need about 1GHz CPU and 1-2GB of RAM, I’ve been using an old 2003 Dell Tower for minimalist Linux, right now Alpine, and a simple web browser, text-based email client, text-based torrent client, text-based IRC client, and like mpv or something
Glaucon: that’s about it
Socrates: no, tell me your use case
Glaucon: that’s my use case
Socrates: what you’re upgrading from
Glaucon: I don’t understand
Glaucon: that’s what I’m upgrading from, that tower, do you want the model
Socrates: OK
Socrates: just get whatever the most-FOSS SBC you can find is
Socrates: but just remember that half of them aren’t actually FOSS
Socrates: (either because they are crippled when running FOSS only, or they ship violating blobs)
Thrasymachus: Way to crush his dreams, Socrates
Glaucon: yeah it’s not a great situation right now
Socrates: Thrasymachus: he wants everything for nothing, the only solution they have is to pay and support showing that its a workable market, or to just deal with compromise
Socrates: or sit on his hands and hope the rest of the world carries them I guess
Glaucon: I don’t want everything for nothing
Glaucon: I want to know what my options are
Glaucon: I don’t know much about open source hardware so I’m learning
Glaucon: I only just jumped off from using Windows 10 daily lmao
Socrates: I really suggest you understand what management is though, because you went from “I don’t know where OpenBMC sits in the stack” to “management bad”
Socrates: so you p much only know the “IME is bad” bit of the story, which is absolutely true, but only one page of a very large book
Glaucon: I never said management bad
Glaucon: I asked if there was anything I could get with no management
Glaucon: to understand the range of these devices
Socrates: you said you didn’t want management at all, which pigeonholes you to “very old” or “very low end”
Glaucon: I don’t mind very old
Glaucon: the problem is very old is often very proprietary as well
Socrates: management is now the default, so you need to make some compromise: remove it, at cost, or pick something old, at a performance penalty, or pick something low end, at a perf penalty, or pick something where the management is open, at a cost
Glaucon: I also wanna avoid x86 bc then I can pigeonhole myself into only using Linux/BSD
Socrates: interesting statement
Socrates: pick x86_64 and you get to run anything, including a better range of Linux, and other interesting stuff like Haiku, Plan 9, etc
Glaucon: that’s the opposite of what I want
Glaucon: I don’t want to run anything
Glaucon: if I did I’d have kept my gaming PC
Adeimantus: then why are you even here?
Socrates: ascetic minimalism and restriction comes at the cost of your own experience
Glaucon: perfect
Glaucon: that’s exactly what I want
Socrates: then get a Filofax and some stamps
Socrates: the computing world is not for you
Socrates: you’ve been had, and you’re taking the /g/ minimal desktop thread meme way too hard
Glaucon: nah, I’m enjoying myself
Glaucon: I just want to take the next step and get more open hardware
Socrates: well
Socrates: you say that but you’re not willing to take what comes with that
Socrates: buying cheap SBCs is usually non-free, even when they have “FOSS” on the sticker
Socrates: usually by taking the allwinner route
Glaucon: because it doesn’t have to be expensive
Glaucon: it is currently
Socrates: the only way to make it not expensive is to support the market now
Adeimantus: it has to be expensive when you have low demand and high costs due to lack of scale
Glaucon: nah
Socrates: like, Raptor are seriously, seriously thinking about pulling from the market
Socrates: because they cant make the economics work
Socrates: because of what Adeimantus said
Glaucon: then buy it yourself? I’m not gonna buy a 1000 dollar PC
Glaucon: it doesn’t have to cost that much
Socrates: like I said, you don’t understand market economics
Socrates: it doesn’t have to cost that much, but you have to overcome a more expensive period to push through to the garden of Eden
Glaucon: the thing is
Glaucon: a cheap chinese SBC is still preferable to an x86 tower
Glaucon: in this case
Glaucon: and I don’t have 1000 dollars
Socrates: OK, but a cheap chinese SBC will not be any more free
Socrates: instead you’re just going to be more limited
Glaucon: a Rockchip is more open than an Intel CPU
Glaucon: lol
Glaucon: not by much but it is
Thrasymachus: Going in circles now
Glaucon: because he’s bitching that I’m not gonna spend a thousand dollars on this PC, and he’s saying I’m not living in reality by saying “the reality is I don’t have that kind of money so I’m going to do what I can to avoid this proprietary shithole on my budget”
Socrates: people like allwinner say they are free, but the fact is they mostly sit somewhere around “never actually discloses source”, “source disclosed builds and runs but is clearly not what shipped and is much lower quality (bait and switch)”, or “rancid GPL violations”
Socrates: I’m fully aware of your goals
Socrates: I’m saying that the volume of options when you’re honest to those limitations is 0
Socrates: so you can either relax cost, or you can relax openness
Glaucon: who do you know that can just relax cost
Thrasymachus: People with $1000
Socrates: most people can relax cost by saving
Glaucon: I’d like to meet them, that they can just decide they have a bigger budget on the fly
Glaucon: I’m relaxing openness
Glaucon: And I still think getting an ARM Banana Pi or something is a better option than buying a new Wintel tower
Socrates: OK, then accept that any SBC you have is going to be loaded with blobs out the foundry
Glaucon: When did I say that I didn’t accept this
Socrates: you came in here saying you wanted to be more open
Glaucon: Okay but when did I say that I didn’t accept that
Glaucon: that doesn’t answer the question I just asked
Socrates: x86 platforms are pretty much more open by the virtue of choice, population of freedom-desiring users, and need to interoperate
Glaucon: it doesn’t feel very open to me if I can only buy from Intel or AMD, that’s not virtue of choice
Glaucon: At least ARM has plenty of companies producing them
Socrates: you know that ARM only sells IP I’m sure
Glaucon: I don’t know what this means, no
Glaucon: only sells Intellectual Property?
Glaucon: as in they don’t make chips?
Socrates: correct

The false promises of ARM

Socrates: most ARM chips are completely non-replaceable by other devices
Socrates: they are interchangeable above the CPU level because they all present an ARM interface to software
Socrates: but the firmware used to make them work is usually non-open
Socrates: so if you buy a chinese SBC, the only people making firmware for that are the manufacturer
Glaucon: it doesn’t have to be Chinese
Socrates: if you ask them for the source, they will generally either not respond, send you GPL-violating source, or send you source code that is clearly not what is running on the board, because it is buggy, slow, or requires significant adjustments to target the silicon
Glaucon: I just said that as an example
Socrates: well, the point is general
Socrates: I’m sorry, but you’ve come into this channel and you seem to have accepted my expertise when you were asking me questions about different architectures like power, RISC-V, etc
Socrates: but now when I’m telling you uncomfortable truth you call it bitching
Glaucon: No I get it
Glaucon: I’m just saying
Glaucon: I still don’t see why I’d buy a Wintel laptop/tower over an ARM SBC
Socrates: ARM SBCs are less open
Socrates: and less capable
Glaucon: less capable I don’t care
Glaucon: less open I get
Adeimantus: “I want to use tech as little as possible and just be done with it”
Adeimantus: “I also want to go out of my way to use the most hipster shit imaginable, exponentially increasing my time spent on this tech I hate and dramatically limiting my options in getting shit done”
Adeimantus: do you even listen to yourself dude?
Socrates: if you just want the cheapest thing you can get as just get on with it, just get the cheap new Raspberry Pi1 that came out
Glaucon: What do you want though, should I just keep using a Windows 10 laptop
Socrates: I want you to drop the pretense
Glaucon: There is no pretense
Glaucon: I want this thing
Socrates: then stop saying that openness is so important to you
Glaucon: it doesn’t exist largely
Glaucon: that’s okay
Socrates: correct
Glaucon: But I can get closer to it
Socrates: or rather, it exists, but outside the limitations you put on your search
Glaucon: well yes it exists in workstation motherboards and such
Socrates: if you want open and cheap, get an Raspberry Pi: the only thing that its really missing is a manufacturer provided GPU driver in free code
Glaucon: yeah that’s probably the best option
Socrates: I’m pretty sure you can still boot it with entirely free software but the perf is abysmal
Glaucon: perfect
Socrates: but its extremely well supported generally, so you’re not going to spend your entire life debugging issues with it and recompiling software with a substandard toolchain
Socrates: but you need to accept that this is not really any more free than a modern x86_64 device
Socrates: where you can run FOSS BIOS, FOSS bootloader, FOSS OS, use entirely FOSS drivers with little restriction in devices, and null out the stuff you cant
Glaucon: it’s also about production
Socrates: and you get way better bang for your buck
Glaucon: only two companies make x86 CPUs
Glaucon: and that bothers me as well
Socrates: to be clear, whatever ARM device you pick, only 1 manufacturer will ever produce that
Glaucon: yes, I’m aware of this
Socrates: this isn’t the same as the analogy you’re drawing in your head
Glaucon: I think you misunderstand
Glaucon: I know only one manufacturer will only ever make any particular ARM device
Socrates: OK, let me reframe it
Socrates: ARM-based chips are motherboards
Socrates: the only replaceable part is the ARM IP core
Glaucon: that’s fine with me
Socrates: everything else in an ARM chip is proprietary
Glaucon: I get this
Socrates: the idea that “only two corps make x86” vs “lots of people make ARM based stuff” is much more like “one one person makes ARM (ARM)” and “but lots of people make ARM/86 mobos”
Socrates: ARM is more restricted at the architecture level (only ARM gets a say because its proprietary IP - any company can use the x86 arch essentially, but only ARM can make ARM processors)
Socrates: but they sell those processors as sub-chips you can integrate onto your own proprietary silicon to make a whole chip
Glaucon: alright alright
Socrates: the example at my company: we had large swathes of silicon specially designed for high speed laser control
Glaucon: I’m trying to understand
Socrates: but we didn’t want to implement the CPU to control it, so we bought ARM silicon to go alongside it on the chip
Glaucon: you were using ASICs for the laser control?
Socrates: yes, but ASIC is a very general methodological term
Socrates: ARM based devices are all ASICs
Socrates: we would prototype on FPGA with ARM softcores and then either deploy FPGAs on the high end products, or where the scale was there, spin a few thousand chips at foundry
Glaucon: this is a big list of licensees
Socrates: but this is what all ARM licensors do: they buy the ARM CPU, then they build interconnect silicon, clock silicon, etc and wrap it
Glaucon: but you’re saying they all all buy ARM CPUs and then just add on to them?
Socrates: yes
Glaucon: no way
Glaucon: really?
Socrates: “ARM CPU” is just basically the ALU, decoder, pipeline, etc
Socrates: this is what they sell as IP
Glaucon: So every ARM CPU does come from the same factories at the end of the day?
Socrates: your job is to wrap it with silicon specific to your market/use case
Glaucon: just like x86?
Socrates: you don’t understand how device manufacturing works, but “yes”
Socrates: ARM sell patterns of silicon wafer that you are not allowed to look at for how it works, but the silicon wafer has known edges that you can interface with, and what you do is put your own silicon up to those edges
Socrates: so only one person “manufactures” ARM, but they don’t actually make any product
Socrates: they sell the patterns of transistors
Socrates: you’re not allowed to look at how they work, but they do let you also buy a manual explaining what the transistors have as an interface, typically memory and control lines
Socrates: like I said, its more like buying a CPU and building the motherboard around it
Socrates: but you put the motherboard into the silicon wafer right beside the ARM CPU instead of connecting to it via the pins on the device package
Glaucon: right
Glaucon: that’s what I was imagining
Socrates: now, its unhelpful to have to physically sell slices of silicon that people weld onto your silicon, so instead they sell the pattern of silicon. you then arrange your pattern of silicon around it, and send the whole thing off to manufacture
Glaucon: so they let you buy the IP
Glaucon: but they only let you know how certain things work
Glaucon: then you can manufacture the CPU yourself, and have your own devices interface with it?
Glaucon: am I getting it?
Socrates: no
Glaucon: okay

Metaphor for software brainlets

Socrates: what is a CPU, describe it to me
Socrates: what does it look and feel like
Glaucon: Well it looks like a small circuit integrated into a small silicon wafer, that’s designed for general case computing
Socrates: no
Socrates: lets move to a software analogy
Glaucon: okay then you explain it
Socrates: most people see a CPU like an executable
Socrates: you buy it and make it part of your system
Socrates: what ARM do is they sell you precompiled library and header files
Socrates: you can then use these to fill in the blanks of your own software and link it into a static executable at the end
Socrates: x86 device: precompiled static executable, a piece of hardware
Socrates: ARM device: precompiled static executable, compromising static objects produced mainly by a manufacturer, but with one ARM static object that only ARM produce
Socrates: there are two manufacturers of x86, there is only one manufacturer of ARM. but whereas you integrate x86 at the chip and motherboard level, you integrate ARM IP at the silicon design level
Socrates: you buy an x86 CPU from Intel or AMD and plug it into your motherboard
Socrates: you buy the equally opaque ARM RTL2 output from ARM and plug it into your own hardware-source-code
Socrates: the only thing you do is the printing of their design onto silicon
Glaucon: so ARM is selling you a silicon design?
Glaucon: and then you produce the IC?
Glaucon: adding on whatever you need
Socrates: yes
Glaucon: dude that’s what I was trying to say earlier
Glaucon: I understood
Socrates: you cant say you understand and then say “but there are more ARM manufacturers than just the two x86”
Glaucon: no well I didn’t initially
Glaucon: but when you started explaining about the IP I did
Socrates: here’s a real example: when people found meltdown/spectre, it only affects Intel, and not AMD
Socrates: if people found something like this in ARM, every single ARM device would be hit
Socrates: because no one produces alternative implementations of ARM
Socrates: is there inter-implementation spying between Intel and AMD? almost certainly
Socrates: but that’s because they’re looking for ways to make their own implementation of x86 better
Socrates: no one produces competing ARM architecture because you couldn’t sell it
Socrates: if you had the skill to reverse it and sell it, you’d turn that skill to competing as not-ARM, like RISC-V has
Glaucon: so essentially
Glaucon: with ARM in the market, we’re no better off than we were before ARM
Glaucon: it’s the same shit
Glaucon: it’s only stuff like OpenPOWER and RISC-V that are actually making any difference
Socrates: ARM is the same shit but worse, because the market is hyperfragmented so there is no coherent userbase to make free firmware on top of ARM based devices, and the fact that they sell arch IP rather than sell an implementation of means that ARM has no competitor
Glaucon: I know I come off as arrogant and stupid but I did already know that the words “free” and “open” are almost entirely buzzwords
Glaucon: nothing is free/open in computers
Glaucon: it’s why the only feasible solution is to lessen your reliance on tech
Glaucon: I mean, I can’t have an open source car, but I can have a horse
Glaucon: is how I’ll put it
Glaucon: has anyone reverse engineered ARM chips?
Socrates: yes, same as people have reverse engineered early x86 devices
Socrates: but reversing silicon of this kind of way is generally uninteresting
Socrates: you don’t need to reverse the silicon to make a competitor x86 processor, likewise, you can implement an ARM processor without ever seeing the silicon than ARM sell

The market realities of reverse engineering

The Ithacan sysadmin Thrasymachus, now intrigued, suspends his heckling to ask a question.

Thrasymachus: This is all very new to me, so I’ll ask the dumb question
Thrasymachus: “Then why don’t people do that? Only legal pressure?”
Socrates: ARM IP targets the people who don’t want to make their own processor. if you can reverse and reimplement ARM, you could make your own non-ARM IP and not pay them
Socrates: its like saying “why does no one reverse engineer a car engine”: if you were in a position where you had the skills to reverse engineer an engine and build one, you probably could just design your own engine anyway
Socrates: the problem is that hardware has far more moving parts, some of which are open and some of which are not
Socrates: free/open in hardware is a multi-layer, multi-dimensional spectrum
Socrates: people think this about software, but its not really true
Thrasymachus: I’m really glad I was awake to observe this
Thrasymachus: I don’t think I’d ever grasped the enormous subtleties of the question “is it open?” as it pertains to hardware before this
Thrasymachus: You have evidently thought about this a lot
Glaucon: everyone who cares about openness has thought about this a lot
Thrasymachus: It’s not fair to say that; I’m ignorant of hardware, but freedom/openness has been a central interest of mine pretty much since I first booted Ubuntu
Thrasymachus: Until Socrates clarified it for you just then, with me watching, I wouldn’t even have known where to begin
Socrates: hardware is much more like a world where everyone implements and sells static libraries, and your end product is an executable
Thrasymachus: This is the first time that has really made sense to me
Socrates: to be clear, the executable here is only a single chip
Socrates: you still need to then build that into a much larger design to be useful
Socrates: hardware is a fractal of complexity with every layer being an abstraction to a whole ‘nother industry
Socrates: software is really easy because everything is self contained and 1D, 2D at most if you count talking across the syscall line

The practical openness of x86

Socrates: actually, why am I still describing this with words
Socrates: here is a single, simple chip based on the AVR architecture (which competes with ARM in very simple devices, think microwave oven)
Socrates: ARM would sell you the black box in the middle called CPU
Socrates: then you as a manufacturer, say, Rockchip, produce the other boxes
Socrates: AMD or Intel pretty much sell just the black box, but they sell it as a chip, and then you implement stuff in the boxes on the mobo
Glaucon: Intel or AMD would sell you the CPU, but as a product, as a finished chip, right?
Socrates: right
Socrates: you can see in that diagram boxes directly above the CPU IP marked RAM
Socrates: in AVR devices and ARM devices, the ram is on-chip
Socrates: (you can also add extended ram off-chip, or only off-chip ram - its your design, after all)
Socrates: the only person who makes ARM is ARM, and they only sell it as that box, rather than a physical chip
Glaucon: so I still don’t get exactly how this makes x86 more open?
Socrates: x86 is made by Intel and AMD, and they sell it as a chip
Socrates: so you have twice as many people producing the same arch, and when you say “there are more ARM manufacturers”, really those manufacturers are more akin to mobo manufacturers
Glaucon: is it just that because there’s two companies making x86, there’s twice as many implementations of the design?
Socrates: that’s a good thing, even though the advantage is not really on the open-ness scale
Socrates: its good because thinks like meltdown/spectre affect only one implementation
Socrates: the open-ness area is where it comes to the mobo
Glaucon: so the solution for now is just buy AMD, or be a tinfoil like me and get a Pentium 4
Socrates: anyone can design a mobo and you can just plug an x86 device in, np
Socrates: with ARM, the mobo is closed source, proprietary, and non-interoperable as well
Glaucon: wait wait
Glaucon: that’s what I’m missing
Glaucon: why does the mobo have to be closed source?
Socrates: the “mobo” being the rest of the silicon sat along side
Glaucon: is it kinda like an NDA?
Glaucon: where you can’t reveal anything about the mobo bc you’d automatically be revealing information about the ARM core itself?
Socrates: the “mobo” for an ARM chip is the silicon that the ARM is embedded into
Glaucon: ahh
Socrates: and the only way you can use this mobo is by the manufacturer like Rockchip giving you blobs to drive it
Socrates: or, if you’re allwinner, they give you blobs and GPL violating source code that builds different, crippled, blobs
Glaucon: so x86 is literally more free
Glaucon: I see now
Thrasymachus: My mind is full of fuck
Glaucon: Thrasymachus I’m glad it’s not just me

Stage 3: Bargaining

Glaucon: I had no idea the situation with ARM was this bad
Glaucon: everyone touts it as some kind of big improvement over x86
Glaucon: but that’s not true at all
Glaucon: so the solution is still just getting an old Thinkpad with Libreboot
Glaucon: or something pre-IME
Socrates: ARM is better because of design, not openness
Socrates: ARM’s architecture and instruction set makes many fewer mistakes, and carries less cruft than x86
Socrates: which has had to maintain backwards compat with decades of mistakes
Socrates: ARM learned from those
Socrates: RISC-V learns from x86 and ARM, and produces an open IP that anyone can implement
Glaucon: right
Glaucon: I can still boot DOS 1.0 on any modern PC that has a legacy BIOS
Glaucon: (which I love but you know)
Glaucon: not the best for efficiency
Glaucon: hopefully those HiFive boards go down in price
Glaucon: I wouldn’t mind spending a few hundred on one
Glaucon: but 1000 is a bit beyond my capability
Socrates: the problem is that the boards cost is locked up in NRE costs
Glaucon: NRE?
Socrates: so those costs never come down, you can only spread them out
Socrates: non-recurring engineering
Socrates: basically upfront design costs
Glaucon: right
Socrates: if it takes $100,000 to make a design, and you plan to sell 100 boards
Socrates: each board has to be $1,000+materials cost+profit margin
Socrates: if you plan to sell 100,000, you can spread the NRE across them all for just $1 a board
Glaucon: My question is though, would you be able to bring the cost down if you had a simpler CPU, like, a 16-bit or 32-bit CPU?
Glaucon: the simpler the CPU, the simpler it is to design and manufacture, no?
Socrates: you cannot design modern CPUs for cheap
Socrates: the level of complexity is too high
Glaucon: right
Glaucon: I’m not talking about a modern CPU
Glaucon: I’m talking about a 16-bit design, let’s say
Glaucon: like those home-made 8-bit projects
Socrates: sure
Socrates: you can get 8051s for cheap
Socrates: like, a few dollars
Socrates: the AVR device I linked is like $1.50 in quantity
Socrates: maybe $5/ea?
Socrates: but these devices will never be able to drive an Ethernet connection, so you will need to buy an Ethernet chip
Socrates: OR
Socrates: you could buy the silicon IP for the 8051/AVR and put it alongside the Ethernet silicon IP on a single slice
Socrates: and now we’re at the ARM model
Glaucon: I see
Glaucon: but there’s open source 8-bit designs, no?
Socrates: show me
Glaucon: I assumed
Glaucon: maybe I’m stupid
Socrates: I mean, they will exist, as hobby projects
Socrates: but nothing anyone would fabricate
Glaucon: why not?
Socrates: fabrication is expensive, and only declines with quantity, it has significant NRE costs to get the fab design to print
Socrates: so the only way you could make open source, cheap, designs is to sell a lot of them
Socrates: you’re not going to do that unless you can compete with ARM
Socrates: this is exactly where RISC-V is
Glaucon: right
Glaucon: what about simpler designs for embedded systems?
Socrates: simpler designs for embedded are owned by AVR, PIC, and ARM Cortex based devices
Glaucon: neat
Glaucon: I did not know this
Socrates: there is an end-run around fabrication costs, btw
Socrates: so you could produce an 8 bit, FOSS hobby design and release it for free and people can get it into their products at low-cost
Glaucon: end-run?
Socrates: end-run = trick to get around a defensive line/problem
Socrates: instead of smashing through a line of defenders, run around around the end of them
Glaucon: well that’s essentially been my idea
Glaucon: for a while
Glaucon: I’ve seen people make 8-bit CPUs at home
Socrates: the long and the short is that I could give you an 8-bit (or 16, or 32, or 64, or exotic design of my own creation) for nothing and at scale if you so chose
Socrates: so you can work around the costs of fabrication at unknown scale/volume
Socrates: and this is available for RISC-V today
Socrates: in fact, you could probably build a hobby grade RISC-V computer for <$500
Socrates: and I know the tools for it are all available now


Socrates is quiet for a moment, and looks at Glaucon, expecting to be asked how one might accomplish this feat, but the question is not forthcoming; his student has been struck dumb.

Socrates: come on
Socrates: take the bait
Glaucon: fine go on
Socrates: FPGAs
Socrates: but you trade cost and flexibility here for massive losses in openness
Socrates: all FPGA platforms require proprietary toolchains that only run on windows
Socrates: hardware is designed as software with can be synthesised to different formats of output
Socrates: one format is a pattern of silicon and metal layers for chips
Socrates: one pattern is for FPGAs
Socrates: you can use ARM IP cores on FPGAs
Socrates: (this is why its not as simple as selling silicon)
Glaucon: oh yes no I know
Socrates: ace
Glaucon: I’m very aware of FPGAs
Socrates: if you can stomach your silicon being closed source, but ultra-dumb and generic = secure
Socrates: you should probably look at getting an FPGA and putting RISC-V and some peripheral IP onto it
Socrates: I think OpenCores is still around?
Glaucon: # This image link is dead. Does anyone still have it? —Ed
Glaucon: So you see that big blob on there?
Glaucon: One of the engineers for the project took the entire original mobo of the Atari 2600 and recreated it on an ASIC
Glaucon: which Atari then produced themselves and used on the Atari Flashback 2, they were sold in such high volume that they made it at profit without issue
Socrates: cool
Socrates: fwiw, he probably didn’t make it as an ASIC up front
Glaucon: how do you mean
Socrates: he probably made it in an HDL which he demonstrated on an FPGA
Socrates: and then Atari produced it in quantity for the flashback
Glaucon: he may have
Glaucon: this was back in 2003
Socrates: spinning an ASIC costs tens of thousands
Glaucon: I know FPGAs weren’t as common back then
Socrates: FPGAs were common back then
Glaucon: well that’s fair
Glaucon: they also did this for the Commodore 64 plug and play console they did
Glaucon: I always wanted to do this but as an open source 8-bit PC
Socrates: ill trust you
Socrates: the more I think about this
Socrates: the more I think you should buy yourself a cracked FPGA model and get yourself to
Socrates: put RISC-V, some USB/display IP on it
Socrates: and you can get a decent computer where you control the entire thing down to the first layer of silicon
Socrates: the silicon is simulated in another bit of silicon, but FPGAs are not really able to fuck you over
Socrates: you’ll never be able to fully trust the FPGA, but rest assured that if someone was targeting you at the FPGA level, they would be just as able to compromise the foundry if you ever tried to get your design put into real silicon
Glaucon: I wouldn’t mind using an FPGA for developing
Glaucon: it’s just that I want my main PC to be cancer free
Glaucon: but I’m a retard
Socrates: so yeah, get yourself an ICE3 family FPGA and build your own CPU
Socrates: it’ll be faster than anything you can build yourself in actual hardware
Socrates: and easier
Socrates: network:
Socrates: RAM:
Socrates: video:
Socrates: CPU:
Socrates: CPU:
Socrates: USB:
Socrates: put these onto an FPGA and you basically have a working RISC-V computer
Socrates: put it onto an ASIC, and well done, you’re an RISC-V device manufacturer
Glaucon: damn
Glaucon: I had looked at FPGAs to make 386 IBM PC clones
Glaucon: what FPGA do you recommend
Glaucon: I kinda wanna do this
Socrates: I mean, this will probably take 2–3 years of learning and a few thousand dollars
Socrates: but the cost is spread out
Socrates: its things like replacing a $300 FPGA board when you trash the first one
Glaucon: mmmmmmmmmmmmm
Glaucon: well my primary interest is in making an 8-bit PC
Glaucon: which would probably be a bit easier
Glaucon: or a PC based on this
Socrates: well, same hardware covers it
Socrates: just you can get the cheaper variant of it
Socrates: there are various FPGAs that have been reversed well enough to be targeted by FOSS toolchains
Socrates: have a look at the butterfly
Socrates: an AVR will take ½–⅓ of these devices
Glaucon: what’s an AVR?
Glaucon: I still don’t quite understand
Socrates: an AVR is a microcontroller
Socrates: same as a low-end ARM device
Socrates: so its a device with compute IP (AVR rather than ARM) and a bunch of on-board peripherals
Socrates: (for example, a serial port, timer modules, SPI/I2C, USB, etc)
Socrates: AVRs are the microcontrollers used by the Arduino family of development boards
Socrates: if you’re new hardware, start here
Glaucon: can’t I just make a weird FPGA PC with an Intel 4004?
Socrates: sure
Socrates: Arduinos are a much gentler introduction
Glaucon: gentle isn’t my thing

Doing it the hardest way

Socrates: you’re like the guy who comes into #C and says “I want to make an operating system”
Socrates: sure, cool, but start with hello world in python
Socrates: build up to C
Socrates: then build up to the foundations of what you want to do
Socrates: then do it
Socrates: same way: start with Arduino, learn how electronics work, then start with FPGAs, blink a few LEDs, then try your first 3rd party IP, then start thinking about gluing them together
Glaucon: nah nah nah I’ll be gucci
Socrates: OK
Glaucon: I’ll figure it out from the bottom up
Glaucon: from electricity to circuitry to simple circuits to a simple Intel 4004 PC
Socrates: well, enjoy your paint by numbers CPU but you’re going to spent twice as long and twice as much by just slamming yourself into the higher end of it rather than actually learning
Socrates: yes
Socrates: do this with Arduino
Socrates: it solves a lot of the hard stuff and allows you to focus on learning how it works
Glaucon: nah I’ll just buy a breadboard we’ll be gucci
Socrates: then you can ditch the Arduino software framework, write C directly, understand how co-silicon peripherals interact
Socrates: etc
Socrates: OK
Socrates: well
Socrates: enjoy your timing errors, transparent latches eating 30% of your gate count, and parasitic capacitance meaning you can never find a compromise between stable clock and voltage
Glaucon: I will
Glaucon: thank you very much
Glaucon: Can’t I just be like Woz?
Glaucon: Why must you shit on my dreams


Polemarchus the Spartan, having wandered in late, realises the extent of the discussion he has missed.

Polemarchus: hey could you maybe talk about CPU architectures for two and a half hours? oh you already did?
Glaucon: yeah sorry we can do it again if you’d like
Socrates: fuck, people talking tech in #sqt
Socrates: close the damn doors

  1. An 8GB variant of the Raspberry Pi 4 had recently been released: 

  2. Register Transfer Level: 

  3. The Lattice iCE line of FPGAs was one of the only FPGA families to have had its bitstream protocol reverse engineered. This enabled a fully free and open-source toolchain to be produced, unlike any other in the notoriously proprietary space.